Many occupations require personnel to operate under extreme physical stress and/or hazardous conditions. Such occupations are, for example, firefighters, mine workers, military personnel, ship yard workers, chemical industry personnel, athletes, permit required confined space applications (as defined by OSHA) or personnel working in asbestos removal projects. The physiologic condition of personnel working in hazardous environments, and/or with high physical stress is a vital concern. It is desirable that the physiologic condition can be monitored on an ongoing real time basis. In particular, it is desirable to monitor the physiologic condition of the personnel in combination with the physical location of the personnel.
Generally, physiologic sensor systems have been developed to monitor patient's physiologic status in a clinical setting. Monitoring healthy personnel working under stressful or hazardous conditions, however, differs in several essential ways from monitoring patients in a clinical setting. While some physiological parameters will likely be common in both instances, the types of sensors used and the data processing and data management is different in critical ways. Most non-invasive patient monitoring focuses on detection of alterations in temperature, heart rate or rhythm, blood pressure or oxygen saturation. These observations are recorded and analyzed under environmentally controlled conditions with the patient at rest or engaged in tightly limited physical activities. Under these controlled conditions, it is a relatively simple matter to attribute deviations from baseline values to pathologic states that require medical attention. Additionally, real time recognition of potentially significant physiologic events in monitored patients does not require complex analysis. Relatively narrow limits defining tolerable values can be established and readings outside of these limits can then be used to trigger alarms. The medical personnel monitoring the output of the sensor instrumentation would then perform the more complex information processing including integration of the data from the sensor array with the clinical history and circumstances of the patient.
Application of current real time medical monitoring technology to personnel engaged in stressful activities such as, fire suppression, chemical clean up, asbestos removal or military activities, presents substantially different circumstances. Specifically, access to the biological data of the worker must be gained without compromising response times or compromising the protective equipment worn by the personnel. This means that sensors have to be incorporated into the equipment such that the signals from the sensors can be reliably transduced and amplified without motion artifact regardless of the local sweating, incident trauma or other stress on the personnel. This must be accomplished while maintaining both the integrity of the protective material and the sensor seals.
For example, a firefighter cannot be further encumbered by either significant weight or by extensive wiring or tethering. The sensors and supporting instrumentation need to be able to withstand environmental conditions ranging from subzero to blast furnace temperatures, toxic atmospheres and the inevitable physical battering. Beyond the physical restraints placed on the sensor system, the sensor system must also be able to react to extreme variability in vital parameter values that characterize individual physiologic response to extreme environmental stress and exertion. Furthermore, the sensor system must be able to provide useful real-time information for decision makers receiving the processed output from the sensors.
Specifically, in a firefighting environment, fire ground is a high hazard environment that requires constant vigilance by emergency responders. Personnel working in a fire scene must be able to quickly identify and adapt to rapidly evolving threats. Any information from a physiologic or environmental monitoring system must be presented to such individual firefighters in a clearly useful format while minimizing non-essential distractions. A continuous numeric readout of oxygen saturation values, for instance, would divert a firefighter's attention from his surroundings and divert his attention away from more urgent fire ground queues. The information from an individual firefighter's entire sensor array must be returned to him in a format that simply indicates the ability of it's safe to continue or it's necessary to evacuate the hazard zone. While it is important that only this minimal critical level of data be presented to the firefighter, the amount of information necessary to return this minimal level of data must be monitored on a continuing basis and analyzed over a significant period of time. Particularly, more specific information concerning physiologic parameters such as pulse rate, oxygen saturation, or carbon monoxide, must be available to personnel keeping track of larger numbers of workers in the hazardous situation.
The prior art discloses apparatus that is directed to individual sensor problems but does not disclose apparatus that integrates a sensor system directed at critical physiologic parameters with a position sensor system and apparatus for real time processing and display of the sensor data. For example, the prior art discloses general sensors mounted in a self-contained breathing apparatus mask. This art does not disclose specific sensors for sensing critical parameters monitored in hazardous environments. It also does not disclose any solution to the problem of processing the sensor information in real time. Other references disclose monitoring systems for physiologic parameters that are not integrated into SCBA systems and that do not display different information to various personnel.